I've used an assortment of different hollowpoint duty loads and a little Ball ammo in mine.
If I focus, I can obtain 1-hole groups out to 15yds, shooting 2-handed unsupported.
I've experienced some 5" & less groups at 50yds shooting both standing, 2-handed, unsupported and kneeling.
It has pretty much equaled the practical accuracy of my 1911's at the same distances.
I've seen some other shooters (even instructors) struggle with it a bit in order to make 3" groups at 15 yards, though.
Then again, one guy who carries an issued 4566TSW and owns a G21SF was immediately able to shoot my M&P 45 better than either of the other guns, and ordered himself a M&P 45 pretty quickly.
Overall, the M&P 45 has surprised me by its inherent accuracy.
Although I'm not a target/sport/competitive shooter, nor do I bother with "benching" pistols, I'm pretty sure the pistol is capable of better than I've been able to accomplish with it. I'm the weak link in the equation.
The revolver-like trigger takes some adjustment for shooters of some other designs, such as the 1911 & Glock, but being a long-time revolver shooter I felt like I adapted to it fairly easily.
The initial stiffness of the trigger required some effort on my part, although it was consistent & predictable. Once it started to smooth out and lighten up it became much easier to shoot with the same accuracy (going from initial 8 1/2 - 9lb averages down to 5 1/2 - 6lbs a couple of thousand rounds later).
I'm going to try a M&P 45 with the APEX sear in the near future (belonging to another instructor) to see how it does.
I've handled and used some other plastic .45's ... G21, G30, G21SF, G36, SW9945, HK P9S45 (part plastic

), Wilson KZ45, along with some other plastic 1911's and HK USP/USPc .45's. Of those, the HK P9S & USP's were similarly accurate, although I didn't care for the overall ergonomics or triggers.
I think the M&P 45 makes for a very good 'defensive/service pistol'.
Having carried and owned a couple of different 4513TSW's, and having handled and fired a M&P 45c a couple of times, I can do better, more easily, with the M&P 45c. Weird ... and I really like the S&W TDA 3rd gen guns ... but there you go. When I get around to ordering my M&P 45c I doubt my original 4513TSW will see much use outside of occasional range practice. My CS45, maybe, just because it's smaller and I've spent a LOT of range time enjoying the diminutive TDA .45, but the M&P 45c is something I anticipate carrying more often than any of my other 9 pistols chambered in .45 ACP.
